Flotation of oxides



Patented Apr. 9, 1935 UNITED STATES FLOTATION OF OXIDES Ludwig J. Christmann,

A. Falconer, Elizabeth, N. J.,

American Cyanamid Jersey City, and Stuart assignors to Company, New York,

N. Y., a corporation of Maine No Drawing.' Application August 12, 1929,

Serial No. 385,472

8 Claims.

This invention relates to a process of recovering oxide ores as distinguished from those of the sulphide type by subjecting the same to a flotation operation.

Throughout this specification where the word oxide is used, it is intended to designate ore comprising substantially non-sulphide compounds. While, of course, some oxide or oxidized ores contain as much as 5% sulphide, yet as far as this discovery and invention is concerned, such sulphide is present only incidentally, and though a part of the metals present as such may be recovered, yet it is primarily intended to float the oxides and particularly the definite chemical compounds such as oxides and carbonates of the heavy metals.

Heretofore it has been a very common practice in the treatment of oxidized ores to first sulphidize the same in order to convert the non-sulphide compounds to sulphides to make them amenable to the flotation reagents, but this invention and discovery does not find such a procedure necessary as the oxides may be floated directly by the process hereinafter set forth.

Certain reagents specified in this application are well known in the recovery of sulphides, but it does not necessarily follow, and as a matter of fact, there is no theory of reasoning by which one would conclude that a sulphide flotation reagent may be efficiently used for the recovery of oxides. Actual flotation experience heretofore has distinctly shown the reverse to be true. According to prior practice in sulphide flotation, either the values present as non-sulphides were lost or they were given a preliminary treatment to convert them to a sulphide form. As an alternative, they were frequently given further and different treatment to recover them as such.

We have discovered that the substituted dithiophosphoric acids and their salts are particularly efficient as flotation reagents in the recovery of oxide minerals.

As demonstrating the invention, an ore comprising a copper carbonate such as malachite was ground to less than 200 mesh, and a sample thereof was subjected to a flotation operation with the following reagents in a mechanically agitated flotation machine:

Reagent A comprises the sodium salt of dicresyl dithiophosphoric acid.

Reagent B comprises di-isopropyl dithiophosphoric acid.

Reagent C comprises di-amyl dithiophosphoric acid.

Using 2.72 lbs. of reagent A per ton of ore with a 50 gram sample of malachite, a froth floated 74.8% of the copper. In this operation a very voluminous froth was obtained. Under the same conditions but using only 1.36 lb. per ton of reagent A only 30.8% of the copper was floated.

A further float was conducted with reagent A and as high as 93.6% of the copper was floated where 7.04 lbs. per ton of the reagent was used.

Using the same ore and reagent B to the extent of 3.84 lbs. per ton recovered 53.6% of the copper. m In this experiment no separate frother was used. When the same proportion of reagent B was used in connection with 0.54 lb. of pine oil per ton, a copper recovery of 87.0% was had. The same amount of pine oil used in connection with 15 5.76 lbs. per ton of reagent B floated 88.6% of the copper.

A float was conducted using reagent C as being another substituted dithiophosphoric acid to the extent of 6.04 lbs. per ton with the result that 70.0% of the copper was floated.

The above tests would appear to indicate that the dithiophosphoric acids were particularly applicable to the flotation of oxidized ores and specifically to that form of oxidized copper ore existing as malachite.

As a check on the amenability of oxidized ore to these reagents, a float was conducted using cuprite as the mineral, preliminarily treated as in the case of malachite, and 5.76 lbs. per ton of reagent A. This gave a recovery of 91.0% of the copper.

- A further experiment was conducted using azurite as the mineral, and 2.88 lbs. per ton of reagent A floated 94.5% of the copper.

The oxidized lead ores were also found to be amenable to the dithiophosphoric acids, as when a float was conducted using the lead carbonate cerussite, 1.44 lbs. of reagent A per ton floated 97.4% of the lead. 4

It is to be clearly understood that the results here set forth are merely indicative as to the types of reagents found eflicient in the flotation of oxidized ores. Obviously, the amounts of reagents used are not considered absolutely necessary and we therefore do not wish to be limited to the proportions indicated, as the discovery lies principally in the fact that certain reagents may be used with exceptional advantage in flotation processes for the recovery of heavy metals from non-sulphide or oxidized ores.

What We claim is:

1. A method of ore flotation which includes the step of subjecting an oxidized ore containing oxides or carbonates of heavy metals to a froth 55 flotation operation in the presence of a dithiophosphate.

2. A method of ore flotation which includes the step of subjecting an oxidized ore to a froth flotation operation in the presence of a di-substitut'ed dithiophosphate.

3. A method of ore flotation which includes the step of subjecting an oxidized ore containing oxides or carbonates of heavy metals to a froth flotation operation in the presence of a salt of a substituted dithiophosphoric acid.

4. A method of ore flotation which includes the step of subjecting an oxidized ore containing oxides or carbonates of heavy metals to a froth flotation operation in the presence of a sodium salt of dicresyl dithiophosphoric acid.

5. A method of floating oxidized copper ores which consists in subjecting the same to a froth flotation operation in the presence of a di-substituted dithiophosphate.

6. A method of floating oxidized lead, ores which consists in subjecting the same to a flotation operation in the presence of a di-substituted dithiophosphate.

'7. A method of ore flotation which comprises subjecting an oxidized ore containing oxides or carbonates of heavy metals to a froth flotation operation in the presence of a diaryl substituted dithiophosphate.

8. A method of ore flotation which includes the step of subjecting an oxidized copper ore to a froth flotation operation in the presence of a material havingthe probable formula:

where R and R1 represent aryl or alkyl groups and X represents analkali metal group.

LUDWIG J. CHRISTMANN; STUART A. FALCONER. 

